


When Explosions meet Kunai

by karma_is_a_turtle



Category: Naruto, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: Alternate Universe - Reincarnation, Dimension Travel, Gen, Mature Bakugou Katsuki, Older Bakugou Katsuki, Reincarnation
Language: English
Status: In-Progress
Published: 2019-07-20
Updated: 2019-07-20
Packaged: 2020-07-09 07:02:23
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,551
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19883566
Author URL: https://archiveofourown.org/users/karma_is_a_turtle/pseuds/karma_is_a_turtle
Summary: In which Bakugou Katsuki with explosive sweat becomes Bakugou Katsuki with ninja powers.





	1. Prologue

**Author's Note:**

> New story! Hurrah!

* * *

" _Bakugou Katsuki...do you have any last words?"_

" _F..u..ck...yo..u..."_

" _How typical of you, regardless, the poison is already setting in. Your friends are too late. How sad. What a pitiful death for the Number_ _ **2**_ _Hero."_

' _...sorry...Deku...'m gonna... die...anyway…'_

" _Hm, what are doing? HEY! WHAT ARE YOU DOING!"_

" _D..ie…"_

' _ **BOOM'**_

' _ **BOOM'**_

' _ **BOOM'**_

* * *

"See?" A man in a white suit laughed as he lounged on a cloud-like throne. "I knew he'd turn out all right in the end, the kid even gave up his life for a good cause."

A woman in a white dress tsked, staring at the holographic image with distaste. "This _is_ the one who told his friend to kill himself, right?"

The man frowned, glancing at the woman leaning on the edge of their throne. "Now, now, Mary," he chastised, "don't hold something the kid did in middle school over his head _now._ Besides," he grinned, "the kid apologised."

"Yeah, yeah, whatever," she grumbled, pushing herself onto the throne with the man. "So, what are you going to do with him now? You bagsed this one."

The man smirked, waving a hand to get rid of the holographic image and bringing up another one. "Reincarnation," his grin stretched further, "memories _intact_.'

Mary narrowed her eyes, leaning forward to study the image. "But Ali," she frowned, "this world already has a decent ending for that generation. Why add another factor to it?"

Ali grinned, sitting up and stretching. "It's fine, I'm just going to spice it up a bit."

Mary groaned, dragging a hand down her face. "Of course you are."

Ali laughed, his chortles echoing all around the empty, cloudy room.

* * *


	2. Chapter 1

**Summary for the Chapter:**

> efdcz

* * *

"And on Team 7 we have Uzumaki Naruto, Uchiha Sasuke, and Haruno Sakura under Hatake Kakashi."

Katsuki tsked, turning away from his deskmate's loud complaints.

"NO FAIR, NO FAIR," Naruto wailed, shaking Katsuki relentlessly, "WHY DO I HAVE TO TEAM UP WITH THAT BASTARD!"

Katsuki sighed, glaring at the blonde boy. "Oi, Whisker-Face," he whispered, eyes glinting menacingly, "stop shaking my fucking shoulder."

As always, Naruto only pouted. " _Katsuki,_ " he whined, letting go of Katsuki's arm, "call me _Naruto,_ not _Whisker-Face!"_

It appeared Naruto wasn't the only one with complainants. On the other side of the room Sakura was making her reluctance well known. "AH," she screeched, tugging at her hair, "why am I with the _dead-last_!"

Naruto's head snapped towards the pink-haired girl, "Eh, Sakura-chan!" He lamented.

Faced with the commotion of his teammates, even Sasuke managed to grace the class with a derisive tsk.

" _Ehem,"_ Iruka-sensei cleared his throat, drawing back the students' attention, "anyway, on Team 8 we have Hyuga Hinata, Inuzuka Kiba, and Aburame Shino under Yuhi Kurenai. On Team 9 we have Shibuya Soku, Bakugou Katsuki, and Sahori Hima under Nara Shikaku."

From the back of the classroom, Shikamaru yawned, narrowing his eyes at the teacher as he did. "I didn't know Tou-san was taking a team on," he muttered to Choji, who was stuffing his face with chips. Shikamaru leaned his head on his own arm. "Isn't he too busy to take on a team? It's not like they're anything special, well, apart from," he glanced at Katsuki, "him."

Choji shrugged, still stuffing his face, "I mean _-chomp-_ then that's probably why _-chomp-_ Katsuki has always been _-chomp-_ weird."

Shikamaru hummed. "Maybe."

Katsuki, meanwhile, was being confronted by one of his teammates at the front of the classroom.

Soku smirked at the boy, banging a fist onto the desk he was leaning on. "So, _Katsuki._ Looks like we're teammates," he sneered, "make sure you get that stick out of your ass during our missions, otherwise, we might have some...issues, _orphan._ "

Naruto jumped onto the desk at the insult, grabbing the boy's collar. "YOU TAKE THAT BACK!"

Soku tsked, grabbing the boy's wrist and throwing him to the side. He glared at Katsuki. "You got anything to say to me?"

Katsuki ignored the boy, only glancing at the floor, where Naruto was nursing a bruise.

"OI," Soku snatched his collar, "PAY ATTENTION!"

Katsuki glared at the boy, limp in his grasp. "I'll give you one chance," he whispered, " _fuck off._ "

Soku sneered. "Like you have any right-"

_*slap*_

Naruto blinked at the brown-haired boy now lying next to him. An ugly bruise marred his cheek as the boy flailed around in pain.

"SOKU! KATSUKI! STOP FIGHTING!"

Katsuki tsked in response, turning away from his teacher.

Iruka-sensei only sighed. "Anyway, Team 10…"

* * *

"So, what do you think?"

Shikaku frowned, bending down to observe the crystal ball. "Rash, but justified, I suppose."

The Third Hokage sighed, waving his hand to dissolve the image. "I apologise for putting you in this position, you are now a Jonin Sensei, as well as Clan Leader and Jonin Commander."

Shikaku sighed, rubbing a hand on his temple. "How troublesome."

* * *

Katsuki, in his thirteen years of living in the Elemental Nations, had perfected the ability to turn a deaf ear to his surroundings while still being aware of them. It was a thin line to tread, but Whisker-Face helped immensely in polishing it. The kid was fucking clingy.

"Nara Shikaku, here to pick up Team 9." A man walked into the classroom, his eyes roaming over the students before landing on him. The man smiled.

Katsuki sighed, studying his supposed teacher. Tresses of raven hair were clamped into a high ponytail, flaunting a wide forehead marred with a single scar. Another scar jutted his left cheek, beginning well away from his goatee. The man wore a short-sleeved mesh top, paired with a deerskin coat and flak jacket.

When no one else moved, Glasses-Girl stood up and tentatively waved at their teacher. "T-That's us."

' _Like he doesn't know that,'_ Katsuki thought, scowling as he heaved himself up and trudged alongside his teammates. ' _Probably has all our files and records tucked away somewhere.'_ Katsuki scrutinized his teacher as he led them out the Academy and through Konoha. ' _Nara Shikaku,'_ he silently mused, ' _Jonin Commander and Nara Clan head, renowned as a Master Strategist.'_ Katsuki narrowed his eyes, ' _why would this bastard take on brats like us?'_

The man stopped. "Ah, we're here."

Asshole frowned, glancing around him. "Why'd you take us to an empty clearing? This place isn't even a training ground."

Katsuki only tsked, plonking himself down on the grass. His teammates hesitantly did the same.

Their teacher smiled at them, sitting down himself. "As you guys must know, my name is Nara Shikaku." He looked at them expectantly.

Asshole smirked, puffing out his chest confidently. "My name is Shibuya Soku."

Glasses-Girl laughed awkwardly, hugging her knees. " A-And my name is Sahori Hima."

Katsuki glanced to the side, a sneer on his face. "Bakugou Katsuki."

"Alright," The man yawned, "first of all, I must congratulate you on passing your Genin Exams, you guys are now official Shinobi, _but,_ " he paused, scanning over the three of them, "not _all_ Genin who pass will be placed with a Jonin."

Asshole sat up immediately, glaring at the man. "What do you mean by that!?"

Glasses-Girl started trembling. "W-What?"

Katsuki only sighed. ' _So that's why there are so few Genin teams,'_ he scowled, ' _makes sense, but what a fucking troll.'_

Their teacher smirked at their reactions. "You see, Jonin have the choice to take on the team or not. Most of them give their students a test, should they pass, they become students, should they not, the students have the option of either going back to Academy or moving to the Genin Corps." He smiled, "so, would you like to do your test now or tomorrow."

As expected, Asshole leapt up immediately. "I'LL DO IT NOW!" He made fists with his hands and began punching the air. "You gonna fight us or something."

Glasses-Girl held out her hands placatingly towards Asshole. "N-Now, maybe it would be best to wait-"

The man narrowed his eyes at the pairs reactions before turning to Katsuki. He smiled, "what about you?"

Katsuki shrugged. "Tomorrow, I guess."

Asshole sneered at him. "You too _scared,_ orph-"

Their teacher clapped his hands together, interrupting the other boy, "well then," he said, grinning, "Shibuya Soku," the boy puffed out his chest, smiling cockily, "you fail."

"WHAT!" Asshole yelled, grabbing their teacher's collar, "YOU HAVEN'T EVEN SEEN ME FIGHT! HOW CAN YOU FAIL ME!"

The man shrugged, clasping onto the wrist holding onto his collar. "You're rude," he twisted the boy's arm, "rash," he bent the boy flat onto the ground, "and annoying," he held a kunai next to the boy's throat. The man sighed, "so, you fail." He turned to Katsuki and Glasses-Girl, tucking away the kunai, "you two can come back tomorrow for the actual test." The man stood up and stretched, yawning as he walked off.

"W-what the fuck?" Asshole murmured, face pale as he curled up on the ground. "I can't fail, I'm not supposed to fail, this can't be happening, this isn't supposed to happen."

Glasses-Girl covered her face with her hands, trembling as she did. "I-If Soku failed, t-then how am I supposed to pass?" She stuttered, moisture already pooling crevices of her palms. "I'll fail for _sure_!"

Katsuki stood up, eyeing his teammates dispassionately. " _A chick with no confidence and a loser with a mean streak, they're the two types of people doomed to fail if they have no other redeeming qualities.'_ He tsked, turning and walking away from the pair.

' _But why put them with me?'_

* * *

"It's like you predicted, Hokage," Shikaku sighed, leaning on the wall of the village leader's office, "the other two seem hopeless, I've already failed one."

The Hokage raised an eyebrow at him. "Already? What if the other two are acceptable, then what will you do?"

Shikaku shrugged. "Grab someone from the Genin Corps, these kids aren't the only ones who need guidance from a Jonin."

The Hokage grimaced, taking a puff from his cigarette. "What about the boy?"

Shikaku exhaled. "Behaved like the Academy Reports said he would, though he didn't appear particularly compassionate for his teammates," Shikaku narrowed his eyes, "but perhaps he figured something odd about the team arrangement and deemed them a lost cause."

"Perhaps," the Hokage mused, scratching his beard, "I wouldn't be surprised. The teachers _did_ claim him to be a genius on par with Itachi."

Shikaku frowned. "Then is it wise to single him out like this? Wouldn't he be more comfortable in a normal Genin environment? We don't need another Itachi."

The Hokage sighed, taking another drag from his cigarette. "There were a lot of factors in Itachi's upbringing that Katsuki does not have. In fact, I believe Itachi's team and Sensei ended up being a source of frustration for him." The Hokage looked at Shikaku appraisingly, "take good care of Katsuki, Shikaku, and watch him closely."

Shikaku smiled wearily. "Of course, Hokage-sama."

* * *

Katsuki sighed, glancing over the emptiness that greeted him every time he clicked the apartment door open. "I'm home," he called out. No one answered him, as usual.

He made his way towards his bedroom, dumping his bag by the door and collapsing on the bed.

' _A Sensei, huh,'_ his mind briefly flickered to the image of a scruffy, red-eyed hero. Katsuki groaned, burying his head into his pillows. "Stupid brain," he grumbled. There was no point in thinking about the past. He'd never see them again anyway, so what was the use?

"KATSUKI!" The door burst open and an orange figure darted through the apartment. Whisker-Face grinned as he spotted Katsuki lounging on his bed. "I'M HERE!" The boy took a leap of faith, jumping towards the bed and-

"OW!"

Whisker-Face crashed into the wall, a bruise resembling that of a foot marred onto his cheek. He pouted. " _Katsuki,"_ Whisker-Face whined, clambering to his feet, "why do you _always_ do that?"

A set of veins visibly protruded on Katsuki's forehead. He took a deep breath. ' _He's only twelve, he's only twelve, he's only twelve.'_ " _Whisker-Face,"_ Katsuki whispered with barely concealed venom, "why do you feel the fucking need to this same fucking thing every _day._ "

The boy only shrugged, sticking his tongue in a supposedly innocent way.

He sighed, shuffling off the bed and towards the kitchen. He glanced back at Whisker-Face, who was trailing behind him. "Well then," he stopped at the stove, "who's the asshole this time?"

Whisker-Face brightened up immediately, plonking himself down at the dining table and going off on his daily rant. "Teme was such a prick today...Sakura-chan was cute, though...our Sensei was late...both really mean…"

Katsuki ignored him for the most part, only picking out the important details as he paced around the kitchen.

"...and he said once only _nine_ people in a class passed, which is so unfair, I worked hard to pass, you know-" Whisker-Face paused abruptly, sniffing the air. His mouth watered. "Is that-"

A steaming plate of food was placed on the table. "Katsudon," Katsuki answered. He sighed, sitting down as well.

Whisker-Face grinned, clapping his hands together. "Thank you for the food!" He grabbed a plate and dug in, smiling harder as he did. He held his cheeks in delight. "This is _almost_ as good as ramen!" Whisker-Face exclaimed, mouth full. As he tucked in he continued chatting, "you know," he said, "it never fails to surprise me how such a grumpy person can be such a good cook - and a fast one at that."

Katsuki only scoffed, taking a bite of his own food. "I didn't cook this now, idiot. I just reheated it." He scowled as the boy tried to choke out a reply. "Chew than speak, dumbass, you're spraying shit all over me." He handed the boy a glass of water, which he took a big gulp from.

" _Eh-hem_ , anyway, I wish you were on my team," Whisker-Face pouted, "Iruka-sensei said that they always put the dead-last and top rookie together, so if you had beaten Teme we would have been on the same team." He scowled, "why don't you ever try against that prick, everyone knows you're better than him - himself included!"

Katsuki shrugged. "I don't care, that's why." He raised an eyebrow at Whisker-Face, "you were saying something about a secret test?"

"Oh yeah," he frowned, "Kaka-sensei said once only nine people in a class passed it."

Katsuki narrowed his eyes. ' _Nine people, so three full teams. But our teacher has already eliminated one person, so how do those numbers work?'_

"Did you guys get a test?"

He nodded distractedly. "Not yet, but Assho-Soku's already been kicked out."

"WHAT!" Whisker-Face stood up, paling immensely. "They're _that_ tough?"

Katsuki shrugged. "Probably."

Whisker-Face placed his chopsticks on the table carefully, before sprinting out of the apartment. "I-GOTTA-GO-TRAIN-SEE-YOU-LATER-KATSUKI!"

Katsuki snorted, taking another bite. "Idiot."

* * *

"So," Shikaku yawned, eyeing his maybe-students, "are we ready for the test?" The three of them were back on the empty hill, a place with lush greenery and passive animal life. It was his and Shikamaru's favourite cloud-watching place.

Hima gave him a shaky nod, not even daring to look him in the eyes as she fiddled tips of her skirt. The girl didn't look prepared to do a mission, mentally and physically. She didn't appear to carry much weaponry nor any seals to hold them, despite bukijutsu being one of her few strong points. The girl appeared tense and unstretched, wore a dress that was a hindrance, and didn't even bother tying up her hair.

Shikaku frowned. ' _Unless she's got some secret skill she's been hiding, I doubt I'll pass her.'_ He turned his gaze to his other potential student.

Katsuki kept a default scowl on his face, only tsking in response to the greeting. Unlike his female counterpart, he appeared to be much more prepared. Shikaku could spot scrolls tucked into his pockets and even managed to catch a glance of one of his signature explosive kunai. Katsuki was slightly tensed but not stiff, his outfit was composed of a black singlet and pant, paired with a mesh shirt covered with metal plates. Red eyes were narrowed at him, framed by spiky blond bangs.

Shikaku yawned, "well then let's start," he reached into his pocket, pulling out a storage seal. Both students student stared at the object, one analytically, one fearfully. Shikaku carefully pulled the seal open and smoke began to emerge, "the test will be," the smog cleared, "Shoji."

Hima's jaw dropped. "S-Shoji," she stuttered, scrambling away from the board game, "b-but I don't even know how to _play_!"

Katsuki's scowl shifted to frown. "Neither."

Shikaku sighed, motioning for the girl to come closer, "I suspected as much. I'll tell you the rules and then both of you will play me individually. I'll determine who passes based on that." He dragged a hand down his face. "Where to start? Let's see...so the general aim is to protect the king who can like this - each pawn can move differently, by the way, so what you want to do is…"

As Shikaku explained he took note of the pair's reactions. Hima appeared to cling to every word he said like a lifeline, trembling even harder when he got into the real intricacies of the game. ' _Too trusting,'_ his mind mentally noted. Katsuki seemed to apply the right amount of deliberation to what he said, occasionally asking questions and being overall thoughtful about it. Shikaku inwardly sighed, glancing at Hima, ' _all she's really doing at this moment is painting Katsuki in a better light - they're the exact picture of Shinobi do's and don'ts.'_

"Alright," he said, once he finished explaining, "who would like to go first?"

Hima, as she had done for the last half hour, trembled and fidgeted, Katsuki looked contemplative.

Shikaku inwardly smirked. ' _From a strategic point of view, going first is definitely disadvantageous, and they both know that. Hima, with her crippling anxiety, is highly unlikely to volunteer - which I'm sure Katsuki knows. So, will he take one for the team, or will he pressure her regardless?'_

Katsuki sighed. "I'll go."

Shikaku raised an eyebrow, setting up the board on the grass and motioning for the boy to sit opposite him. "Do you want to go first or should I?"

Katsuki shrugged. "You go."

Shikaku grinned. "Let the game begin."

Katsuki was an interesting player, Shikaku decided. At first, he appeared to move the pieces at random, all the while carefully observing Shikaku's every move. After a couple turns he appeared have gotten the hang of it, spreading his pieces out with some semblance of a strategy. Hima was, thankfully, watching their game astutely, as ten minutes turned into an hour, and one hour turned into three.

"You won."

Shikaku glanced up at Katsuki, raising an eyebrow. "What do you mean by that?"

Katsuki sighed. "You'll win in 15 moves."

Shikaku smirked. "We'll see." Katsuki was right, of course.

Fifteen moves later Katsuki was smirking at him. "Told you."

Shikaku smiled, resetting the pieces. "You're quite smug for someone who just lost."

Katsuki shrugged. "Didn't expect to win, anyway."

"T-That was amazing," Hima praised, gaping at Katsuki. "I-It looked really close."

Katsuki snorted. "He had me trailing after him the whole time, I'm lucky I lasted that long." He cracked his neck, stretching slightly before nodding at her. "Good luck."

Hima bit her lip. "R-Right, n-now I play."

' _So watching him play has given her confidence,'_ Shikaku mused, noting the way she clenched a fist, ' _interesting, I thought it would intimidate her.'_ "Do you want to start?"

She nodded. "Y-Yes."

Shikaku frowned as they began to play, out of the corner of his eye he spotted Katsuki doing the same. ' _She's copying his moves.'_ Not all of them, she was rushing it quite a bit, but the pattern in which she moved was similar to that of Katsuki's, whose strategy was commendable. The only problem was that Shikaku wasn't playing Hima the way he played Katsuki. The game was over in ten minutes.

"I-I lost too," Hima gave them a shaky smile, "it went by so quick." She laughed abashedly, before freezing and looking down. "S-So both of us...go back to the academy?"

Katsuki sighed, turning away from her.

"A-Ah, w-well it was a h-hard test so it's fine." Hima smiled.

' _So that's why she's wasn't so nervous, because Katsuki lost as well,'_ Shikaku frowned as he packed away the Shoji set, ' _so she's fine with failing if she fails with a known 'smart' kid, considering she was so distraught after Soku failed. I suppose it looks less bad for her but that's not a good mindset to have.'_

"Bakugou Katsuki," the boy glanced at him, he grinned, "you pass."

Hima stilled, face paling as she stared at Shikaku. "W-Wha-"

"Sahori Hima, you fail." He stood up, motioning for Katsuki to follow. "From now on I'm going to take you on as my apprentice, so we'll talk to the Hokage first."

Katsuki frowned. "The Hokage? Why?"

Shikaku smirked. "You think just _anybody_ can be an apprentice?"

Katsuki hummed. "I guess," he glanced back, eyeing the tearful figure behind them. "What about Glasses-Girl?"

Shikaku sighed. "If she wants to be a Shinobi she needs thicker skin, or she's not going to last," he paused, "Glasses-Girl?"

Katsuki scoffed at him. "She's Glasses-Girl and you're Pineapple-sensei."

" _Pineapple-sensei?"_

**Notes for the Chapter:**

> Katsuki still looks like Katsuki btw


End file.
